gluLookAt creates a fully translated and rotated modelview matrix. Just grab the source for Mesa3D and see for yourself. In there, you will find two gl-commands: glMultMatrix, which does the rotation, and glTranslate, which does the translation.
You are correct, gluLookAt does not give you the upvector, front vector and any other information. But that is completely unecessary, since you already know them.
If you want the viewpoint at A, looking at B, you just put the proper arguments into gluLookAt, and it creats the necessary information for you, so that the modelview matrix is currently located at A, looking at B. Of course, the upvector is, as DFrey said, mostly constat, so that was not mentioned. But since it’s constant you know it.
gluLookAt(10,0,10, 0, 0, 0, 0, 1, 1);
The above code will generate a modelview matrix, that is located at (10, 0, 0), will be rotated so that it is looking at the origin, and view of the origin will be slightly roleld aswell because of the upvector. No magic involved with manual rotations/translations, and other mathematical tricks. Can it be easier?
Are you really sure you know what gluLookAt actually does and how it works? Try read the Red Book…